vduse: Signal vq trigger eventfd directly if possible

Now the vdpa callback will associate an trigger
eventfd in some cases. For performance reasons,
VDUSE can signal it directly during irq injection.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230323053043.35-10-xieyongji@bytedance.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Xie Yongji 2023-03-23 13:30:41 +08:00 committed by Michael S. Tsirkin
parent 5e68470f4e
commit e38632dd71

View File

@ -459,6 +459,7 @@ static void vduse_dev_reset(struct vduse_dev *dev)
spin_lock(&vq->irq_lock);
vq->cb.callback = NULL;
vq->cb.private = NULL;
vq->cb.trigger = NULL;
spin_unlock(&vq->irq_lock);
flush_work(&vq->inject);
flush_work(&vq->kick);
@ -524,6 +525,7 @@ static void vduse_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
spin_lock(&vq->irq_lock);
vq->cb.callback = cb->callback;
vq->cb.private = cb->private;
vq->cb.trigger = cb->trigger;
spin_unlock(&vq->irq_lock);
}
@ -941,6 +943,23 @@ static void vduse_vq_irq_inject(struct work_struct *work)
spin_unlock_irq(&vq->irq_lock);
}
static bool vduse_vq_signal_irqfd(struct vduse_virtqueue *vq)
{
bool signal = false;
if (!vq->cb.trigger)
return false;
spin_lock_irq(&vq->irq_lock);
if (vq->ready && vq->cb.trigger) {
eventfd_signal(vq->cb.trigger, 1);
signal = true;
}
spin_unlock_irq(&vq->irq_lock);
return signal;
}
static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
struct work_struct *irq_work,
int irq_effective_cpu)
@ -1243,11 +1262,14 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
if (index >= dev->vq_num)
break;
ret = 0;
index = array_index_nospec(index, dev->vq_num);
vduse_vq_update_effective_cpu(dev->vqs[index]);
ret = vduse_dev_queue_irq_work(dev, &dev->vqs[index]->inject,
dev->vqs[index]->irq_effective_cpu);
if (!vduse_vq_signal_irqfd(dev->vqs[index])) {
vduse_vq_update_effective_cpu(dev->vqs[index]);
ret = vduse_dev_queue_irq_work(dev,
&dev->vqs[index]->inject,
dev->vqs[index]->irq_effective_cpu);
}
break;
}
case VDUSE_IOTLB_REG_UMEM: {